Electric switch mechanism



Oct. 15, 1929. KNAAK 1,731,580

ELECTRIC SWITCH MECHANISM Filed Sept. 2, 1924 7 3! 7 INVENTOR. By M M A TTORNEY.

Patented Oct. 15, 1929 UNITED STATES.

PATENT OFFICE GEORGE A. KNAAK, OF MILWAUKEE, WISCONSIN, ASSIGNOR, BY MESNE ASSIGNMENTS, TO PENN ELECTRIC SWITCH (30., OF DES MOINES, IOWA, A CORPORATION OF IOWA ELECTRIC SWITCH MECHANISM Application filed September 2, 1924. Serial No. 735,530.

This invention relates to electric switch mechanisms, and the object of the invention is to improve the construction and operation of electric switch mechanisms in the manner to be hereinafter described and claimed.

Referring to the drawings, which accompany this specification and form a part hereof, which drawings illustrate an embodiment of this invention, and on which drawings the same reference characters are used to designate the same parts whereever they may appear in each of the several views, Fig. 1 is a diagrammatic illustration of the electric switch mechanism and associated apparatus; Fig. 2 is a front elevation of the electric switch mechanism; and Fig. 3 is a side elevation of the electric switch mechanism.

Referring to the drawings, the reference their pole pieces 4 and 5 are substantially at right angles to each other and are intersected by a common plane or planes. The specific arrangement described is not of the essence of this invention but provides for a simple and compact arrangement of parts which can be readily and cheaply constructed. The pole piece 4 and the coil 6 of the electromagnet 2 are supported by a frame 7 which can be secured to the panel 1 or any suitable support and in any suitable manner as, for example, by screws 8, and the pole piece 5 and the coil 9 of the electromagnet 3 are supported by a frame 10 which is illustrated by the drawings as secured to the panel 1 by screws 11. An armature 12 is pivoted, by a pivot 13, to lugs 14 and 15 on the frame 7 and has insulating material 16 secured to the lower side thereof and a block 17, which may be also of insulating material, may be provided to afford sufficient thickness for the reception of screws 18, for example. A switch 19, which is preferably formed of spring metal which is a good conductor of electricity, is illustrated as secured by the screws 18 to the block 17 and is provided with contacts 20 and 21 which are adapted to engage contacts 22 and 23 which are supported by the frame 7 and insulated therefrom and to which conductor or wire connections are made so that the switch 19, when closed, that is, when its contacts 20 and 21 are in' contact with the contacts 22 and 23, will form a continuous electric circuit between contacts 22 and 23. The switch 19 is a bridge switch, which bridges across from contact 22 to contact 23 and has no other electrical connection, and, its central part is cut out so that it straddles a projection 24 which is preferably secured to the metallic armature 12 to form a strong and reliable union of the two. A push pin 25 is loosely guided in the frame 7 and, when the armature 12 is drawn towards the pole piece 4 of the electromagnet 2, the push pin 25 is moved and moves a switch member 26 in a direction to make contact with a switch member 27. The extent of this movement is suflicient to separate the switch member 26 from the switch member 28 either before or after the switch member 26 has contacted with the switch member 27. The switch members 26, 27 and 28 may be made of spring metal and the switch member 26 may be retained in contact with the switch member 28 until it has been separated therefrom 32 on the frame 10 of the electromagnet 3 and is normally retracted from the pole piece 5 by a spring 33. The armature. 12 is moved,

away from the pole piece 4 of the electromagnet 2 by the spring tension of the switch 19. The armature 29 is illustrated as provided with a yoke 34 which is provided with an antifriction roller 35. The projection 24 is illustrated by the drawings as provided with a coned part 36 enlarging downwardly, a coned part- 37 diminishing downwardly, and a pin extension 38. The pin extension 38 merely acts as a stopor the antifriction roller 35. The projection 24 is illustrated as'made with the coned parts and the pin extension as a manufacturing" expedient, as this part can be cheaply made on the so-called automatic screw machines and does not have to be given any special attention while it is being assembled with the armature 12. The principle of construction and operation of the coned parts 36 and 37 is to provide substantially arcuate i 1 Wardly extending substantlally arcuate face parts with which the antifriction roller 35 "j can coact in the manner to be nowjdesc ribed When the electromagnet 2 vis-energiz erx, the electromagnet 3- being deenerg'iz'ed, the

. armature 12 willfbe attracted, the switch 19 1 will be closed against its spring tension', and the spring 33 wil1 cause the" armature 29 to be retracted until the antifriction roller 35 15 stopped-by the pin extension 38. The

sWitch'19 will now be locked closed by the armature 29 serying as a lock or latch regardless of-the' deenergiz ation of the electromagnet 2. The unlocking or unlatching of the switch 19 so that it can open is effected byenergizing the electromagnet 3. The upofthe coned part 37 provides an easy runofi for the antifriction roller so that less magnetic force is required to attract the armature 29 during the unlocking or unlatching operation.

Dependable, commercial apparatus must be so constructed that jars or the vibrations of buildings or structures will not cause disengagement of parts. The downwardly extended substantially arcuate face of the coned part 36 should hear. such relation to the anti-.

friction roller 35 that the tension .of the"- spring 33 will not cause an upward movement of the armature 12 and switch -1-9-cither by its own tension or under the influence of jars and vibrations.

Theoretically, the face of the coned part 37 should coincide with the arc of a circle struck from the center of the pivot 30 when the armature 12 is at its limit of movement towards the pole piece 4, assuming that the diameter of the antifriction roller 35 were a mere point. In actual practice the center of I to, to be altered to accommodate the presence the antifriction roller 35 will describe an arc of a circle struck from the center ofthe pivot 30, and the actual surface of the coned part '37 will depend upon the'arc of said circle and the diameter of the antifriction roller 35. The

presence of the antifriction roller 35 requires 1 the arc of said circle, heretoforev referred of the antifrictionroller 35. For example,

the pivot '30 and the antifrictionj roller 35,,

-. looking at Fig. 3: 0f the drawings, the part 37 may correspondwiththe curvature of the antifriction roller 35 from theipin38fto -astraight'linedr'awn throughthecenters of and then. change to a curve upon which the antifriction roller 35 will roll, without encountering resistance, as freely as though it were rolling upon a' single pivot. This latter curveis readily laid out byjdrawingan v are of a circle'with thepivot 30 as a center.

andaradius equal to the distance between the V centenof'the pivot30 and the centerof the 'antifr iction roller 35, and then drawing on" thistarccircles of the same diameter as the diameter -"of thefantifric'tion roller 35-.fan'dvdianieters of these circles ezitending, through see T the center of the pivot 30. A curve drawn through the outer extremities of-these diameters will give the desired curvature. The points to be guarded against are to prevent the tension of the spring switch 19 moving thearmature 29 either by its own tension or as the result of jars and vibrations and that,

when the armature 29 is attracted towards the tially. arcuate surfaces, when short, may not sensiblv'difi'er from straight lines, but the underlying principle of construction and operation is as hereinbefore described.

Referring now to Fig. 1 of the drawings, which is a-diagrammatic illustration of the switch mechanism and a temperature regulating system with which it is installed, the reference' numerals 39 and 40 designate the supply wiresor lines from which electrical' energy is obtained. A- two-blade switch 41 is illustrated as a house or service switch, and, when this switch 41 is closed, a primary circuit 42 is established which includes the primary coil 43 of a transformer 44 which is used to obtain the low voltage current for use in the controlling circuits. An electric motor 45 is adapted to be shunted across the wires 46 and 47 of the primary circuit 42 when the switch 19'is closed and itmay be assumed that the electric motor 45 operates a pump 48 for supplying fuel oil to a burner 49 for heating purposes. The reference numerals50, 51 and i I '52'designate a plurality of thermal responslve devices, which are severally adaptedto cause actuation of the'switch 19-to cause the operation of the electric motor 45' or to stop .its operation as conditions may require.

V are illustrated by the drawings, diagrammatically, as consist- These devices 50, 51 and 52 ing ofthermostatic elements 53, 54and 55 which are conductors of electric current and- 'which .changetheir positions'with variations of temperature.

Switch members 56, 57, 58,

59, 60 and 61 are illustrated as coactingwith'fl 1 the thermostatic elements tablish electrical circuits, perature conditions, and'these switch members 56, 57,158; 59, 60 and til-are illustrated,

53, 54 and 55 to es as=-a m'atter'of convenience, as spring switch members'which move with the thermostatic elements 53, 54 and 55 so that contact between a thermostatic element and-one of its coact ing switch members is always maintained,

and so that a thermostatic element may establish its other contact before breaking the according totem! mostat, the thermal responsive device 51 may be considered as a boiler or other positioned thermostat, and the thermal responsive device may be considered as a pilot light safety thermostat, for the purpose of-this description. The primary circuit 42 is the high voltage circuit for the electric motor 45, and by high voltage circuit is meant a circuit impressed with a commercial voltage for house lighting purposes, for example, A second ary circuit 62 comprises the secondary coil 63 of the transformer 44, the wire 64. the switch member 26, theswitch member 28. the coil of the'electromagnet 2, the wire 65, and the switch member 60 of the room thermostat 52 where the secondary circuit is openor ineffective. A tertiary circuit 66 comprises the secondary coil 63 of the transformer 44, the wire 64, the switch member 26, the switch member 27, when the switch member 26 has made contact with the switch member 27, the wire 67, the coil of the electromagnet 3, the wire 68, switch member 61, thermostatic element 55, wire 69, switch member 58, thermostatic element 54, wire 70, switch member 56, thermostatic element 53, and wire 71 to the secondary coil 63 of the transformer 44.

The operation of the mechanism will 'be readily understood from the foregoing description and the following explanation. Assuming that the thermostatic elements 53, 54 and 55 are in contact with the switch members 56, 58 and 61. conditions are indicated in which the pilot light is burning, the boiler or other positioned thermostat indicates a temperature lower than the predetermined temperature at which it may be set for making contact with the switch member 59, and the room thermostat 52 indicates that the room temperature is such that no more heatis required and, tracing the circuits, it will be noted that the secondary circuit 62 is closed at the switch members 26 and 28 but is open at the switch member and the thermostatic member 55. The tertiary circuit 66 is open at the switch members 26 and 27, and is also open at the switch member 57 and the thermostatic member 53, and is also open at the switch member 59 and the thermostatic member 54 but is closed at the switch member 6]. and the thermostatic member 55 and through the wire 69, switch member 58., thermostatic member 54, wire T0, switch member 56, thermostatic member 53, and wire 71 is closed to the secondary coil 63 of the trans former 44. These connections remain, with a falling temperature in the room, until the thermostatic member 55 has made contact with the switch member 60. Tracing the circuit from the secondary coil 63 of the trans former 44 through the wire 71, the circuit is now closed through the thermostatic member 53, the switch member 56, the wire 70, the

thermostatic member 54, the switch member 58, the wire 69, the thermostatic member 55, the switch member 60, wire 65,electromagnet 2, switch members 28 and 26, the wire 64 to 'the secondary coil 63 of the transformer 44.

The electromagnet 2 is now energized and at tracts the armature 12-, closing the switch 19, and the electric motor 45 is set in operation to supply oil to the burner 49 for raising the temperature. As the armature 12 is attracted by the coil 2, the armature 29 is disengaged from the coned part 36 of the projection 24 and moves under the coned part 37 of the projection 24 so that when the push pin 25 has broken the circuit between the switch members 26 and 28 the armature 29 serves as a lock or latch to hold the switch 19 closed until the electromagnet 3 is energized to unlock or unlatch the switch 19 and armature 12 and permit the switch 19 to open.

The secondary circuit 62 is the switch closing circuit for the electric motor and the tertiary circuit 66 is the switch opening circuit for the electric motor and the protective devices 50 and 51 energize the tertiary circuit 66 to stop the operation of the electric motor when they operate under the conditions against which they are set as protective devices.

It will be noted that the spring 33 illustrated by Fig. 3 of the drawings is a compression spring while the same spring 33 as shown by Fig. 1 of the drawings is an extension spring and the illustration of this spring as shown by Fig. 1 of the drawings is diagrammatic in order to show more clearly at a glance the operation of the said spring.

The reference numeral 72 designates the iron core of the transformer 44 and the reference numeral 73 designates a bridge piece above the end of the switch member 26 and insulated therefrom by insulation 74.

\Vhat I claim is:

1. The combination in electric switch mechanism, of a plurality of electromagnets arranged substantially at right angles and lying in substantially the same plane or planes. movable armatures for said electromagnets, an electric switch adapted to be actuated by one of said armatures, pivots for said armatures, the armature for actuating the switch being provided with a projection having substantially arcuate faces, one of which has relation to its pivot and the other of which has relation to the pivot of the other armature, and a spring for retracting said last ment ioned armature.

2. The combination in electric switch mechanism, of two electromagnets provided with polepieces and frames, an armature for each of said electromagnets pivoted to the respective frames thereof, a spring metal electric switch connected to one of said armatures and a projection secured to the same armature and provided with oppositely diverging ,coned parts and a pin extension, theother armature being provided with an antifriction roller to coact with said coned parts and said pin extension and a spring for retracting said 5 [last mentioned armature. I 3. The combination in electric switch mechanism, of two electromagnets, compris-. ing frames, coils, and armatures .which are pivoted to' the framesrespecti-vely, a, spring 10 metal switch secured to one ofsaid armatures,

' .p a projection provided with oppositely diverg- .ing'coned parts and alpin extension secured tothe same armatureytheother armature being provided with an a ntifriction roller to meet with said coned parts and said pin ex tension, a spring for retracting said last men- Y tioned armature, switchme'mbers, and a plish pin adapted to be actuated in unison with said switchfor actuating said switch members); 20 In witness whereof I hereto aflix my signature. j

GEORGE A. KNAAK. 

